For the recording of scintigraphic images a scintillation camera or gamma camera is used. This gamma camera can rotate step by step on an axis passing through the organ to be examined, to record scintigraphic images at successive incidences, the number of which is generally 16, 32, 64 or 128. On the basis of the data collected during the rotation of the camera, an algorithm of tomographic reconstruction makes it possible to obtain a series of cross sections several millimeters thick.
With a conventional gamma camera, one scintigraphic image per incidence is recorded. As a result, the main drawback of tomoscintigraphy is the slowness of acquisition of the data.